1. Field
This invention generally relates to plugging penetrations in concrete building floors, the penetrations being intended typically for passage of pipes, utilities, and the like.
2. Description of the Related Art
Penetrations, or openings, are commonly drilled in concrete slabs of buildings under construction in order to pass pipes, utilities, and other things through the concrete slab (e.g., a floor under construction) from one level of the buildings to another. The process of core drilling a concrete slab and setting plumbing, fire control plumbing pipes and electrical conduits and fire-proofing the installation on construction job sites is a multi-step process that is labor-intensive. The coring process in a large scale construction project creates many (sometimes hundreds or thousands of) slab bore holes that must be temporarily covered until the pipe installation is complete and the final plugging and fireproof caulking is finished.
Concrete construction utility passage holes are usually bored oversize (by a factor of 2 to 4) beyond what is necessary for passage of a particular pipe or utility. After completion of the slab boring operation with a diamond coring tool, building codes call for a temporary closure of the hole for safety reasons. For example, tools and debris can drop from one floor down onto people and things on lower floors through the hole openings causing injury and economic loss. Additionally, the holes are plugged to prevent people walking on a floor with openings in the floor from falling through or having their feet accidentally caught in the openings.
A common practice to plug construction holes in concrete floors is to use a specially-fabricated wooden hole cover or plug consisting of a shaped (e.g., rectilinear) piece of plywood backed by “2-by-4” structural wood cross bracing that is configured to fit the hole cover so as not to be dislodged by normal construction activities such as walking over the hole cover. The fabrication of thousands of wood cover plates to cover and protect all the core drilled openings in a building under construction is a time consuming and costly operation.
While specially-fabricated conventional wooden hole covers offer some protection from inadvertent accidents by intrusion of people and objects into the exposed holes they do not provide protection from water penetration and leakage, and provide little fire protection. Water from rain or other operations can run down through the holes from one floor to those below it and cause damage or pooling in the lower floors. In a large construction job site, water leakage through floor openings can be a significant problem and a cause large financial losses, e.g., if a storm inundates the site and the water finds its way down many floors through the unprotected holes into areas where finishes have already been applied. Even flooding of an unfinished basement is costly where pumping is required to make the space habitable for continued construction work and to protect the building's foundation.
Pipe fitters tend to work their way through a construction project gradually installing the piping and finalizing the penetrations in the floors. The temporary hole covers are removed and discarded and after the pipes are inserted through the holes, the perimeter around the pipe is stuffed with mineral wool to block the hole and provide a backing for fire-retardant caulking, usually required by building codes, which is hand applied to the top inch or so around the pipe, sealing it to the concrete of the side-wall of the holes. These steps are labor-intensive and thus very expensive.
In light of the above discussion, there is a need for an apparatus and a system that solves most or all of the problems of the current procedure for hole drilling and pipe installation and sealing of the penetrations.